The invention relates to a magazine for use in an analytic test instrument and to an analytic test instrument. Such analytic test instruments and magazines are used particularly in the field of medical diagnostics for generating and/or collecting and/or analyzing a sample of a body fluid. Analyzing the sample can in particular include a qualitative or quantitative analysis of the sample of the body fluid in respect of one or more analytes. By way of example, these analytes can be metabolites. Without restricting further possible fields of application, this analyte can, for example, be blood glucose, cholesterol, triglycerides, coagulates or the like.
The field of medical technology, in particular analytics, has disclosed a number of test instruments that require analytic aids. By way of example, there are known to be piercing instruments, in which a number of lancets can be used in succession, or analytic measurement instruments, in which a number of test elements can be made available in succession in order to detect at least one analyte in a sample of a body fluid.
In addition to test instruments that have drum magazines or similar supply devices for making available the analytic aids, tape instruments are finding increasing use of late; here, the analytic aids are made available by means of one or more carrier tapes. Thus, for example, German Patent No. DE 28 03 345 C2 describes a piercing device for obtaining blood; it comprises a tape magazine. In this case, individual lancets are lined up in succession on a tape. Similarly, German Patent No. DE 198 19 407 A1 describes a blood-glucose measurement instrument with a tape magazine for test strips. In February 2009, the Accu-Chek® Mobile test instrument from Roche Diagnostics GmbH became the first commercially available blood-glucose measurement instrument that makes use of a test strip tape cassette.
The advantage of the tape concept, whether for lancets or for test elements, generally lies in the relatively large number of analytic aids, e.g. test elements and/or piercing elements, that can be available in wound-up form in a comparatively small magazine. However, in general there is the problem here that a tape is relatively difficult to handle in practice compared to rigid carrier elements. Thus, in particular, tape instruments require a few additional technical measures in order to enable orderly guidance of the tape and, for example, prevent uncontrolled unwinding of the tape.
The prior art has disclosed so-called rewind locks for tape magazines, which can fix the carrier tape, particularly when the magazine is removed from the test instrument. This prevents already used-up test elements and/or piercing elements from reappearing so as to avoid the risk of unwanted contamination of the user and/or other parts of the analytic test instrument with a liquid sample or to prevent injury to the user.
Thus, for example, International Publication No. WO 2006/059232 A1 describes a measurement instrument with a test-sensor disk magazine. The disk magazine has a rewind lock which is only activated in the removed state of the magazine; by contrast, this lock is by-passed in the inserted state.
U.S. Publication No. 2009/0200413 describes a diagnostic test-strip tape cassette. It has a rotational safety device with locking teeth that should prevent inadvertent unwinding of test tape. This lock is active in the case of instrument-independent handling.
European Patent No. 1 690 496 B1 describes a blood-glucose measurement system with a test-strip tape magazine. A pawl ensures that a take-up reel, i.e. a holding reel for used-up tape sections of the test tape, can only rotate in one direction. This locking function is active in the inserted state of the magazine.
U.S. Pat. No. 7,883,473 also describes a piercing aid. It has a lancet magazine with an integrated rewind lock. This rewind lock should, in particular, prevent reuse of the lancets used at an earlier time.
International Publication No. WO 03/088835 A2 describes a system that is based on microsamplers stored on a tape magazine. This system is also provided with a rewind lock. A ratchet device ensures that tape transport can only take place in a forward direction. This is how the inserted tape magazine is secured against inadvertent rewinding.
U.S. Publication No. 2010/0216246 has disclosed a combination drive for a sample-obtaining system for obtaining a liquid sample. The sample-obtaining system has a coupling element for coupling to an analytic aid and a drive unit for driving a movement of the coupling element. The drive unit furthermore has a coupling device with at least one rotational-direction sensitive element, with the coupling device being configured to couple an energy transducer to a first system function in a first rotational direction and to a second system function in a second rotational direction.
However, in practice there are a few technical challenges in known test instruments that are based on the use of a tape magazine. In particular, there are test instruments in which a lifting movement is carried out in at least one application position with an analytic aid situated there. By way of example, this lifting movement can be a rapidly carried out piercing movement and/or a slowly carried out sample-taking movement. Thus, for example, a lancet can be used to perforate a skin section of a user and/or a liquid sample of the body fluid can be collected using a test element in the application position. However, a problem in the case of such lifting movements of analytic aids stored on a tape magazine lies in a release of the tape. By way of example, a taught carrier tape only has limited suitability for a piercing or blood-collecting procedure. Releasing the tape enables a deflection of the carrier tape during the lifting movement in which the carrier tape is also moved and as a result avoids overstretching, a lasting deformation or even a tearing of the carrier tape.
U.S. Publication No. 2010/0049090 describes a piercing system with a lancet carrier tape that carries a plurality of lancets. In a piercing movement, the piercing drive moves a lancet brought into the piercing position together with a section of the lancet carrier tape carrying this lancet in the piercing direction. After a lancet was brought into the piercing position, at least one part of a transport apparatus, arranged behind the piercing position in the conveying direction, carries out a movement before or during the piercing movement of said lancet. It is furthermore proposed that a winding apparatus on the inserted cassette carries out a rewinding step in order to unwind carrier tape from the take-up reel for the respective piercing movement.
Hence, in general it should be noted that lancets, test elements or microsamplers stored in a magazine generally require a rewind lock in order to provide the user with the necessary hygiene and safety when handling the medical product. These rewind locks can, in principle, be applied to analytic aids stored in a tape magazine. However, a disadvantage of the known systems is the fact that the presence of a rewind lock is often contradictory to the requirement of a tape release, i.e. reversed tape unwinding during the lifting movement, for example during the piercing or sample-collecting process. However, the tape release in many cases requires rewinding of carrier tape already wound onto the take-up reel because otherwise there would be uneven load on an actuation system of the test systems, e.g. a lancet gripper. By way of example, the consequence of this would be oblique piercing, slipping of the lancet in the gripper, blocking of the piercing actuation system or the like.
Releasing the tape is required in many cases in order to provide deflecting carrier tape to be deflected during the piercing process with enough play. However, for this, most solutions known from the prior art do not provide an answer to the presence of a rewind lock. An active rewinding movement of the take-up reel drive does not suffice in many cases if the rewind lock of the magazine does not support this function or offers other alternatives for releasing the tape.
Particularly in the case of test instruments and tape magazines comprising a permanently acting, integrated rewind lock, it is thus possible to establish that there is a conflict of goals with a lifting movement of a test element. Here, an integrated rewind lock should in general be understood to mean a rewind lock that is integrated into the magazine and thus is able to prevent rewinding without requiring a drive of the test instrument. On the one hand, such an integrated rewind lock is often desirable since it prevents inadvertent unwinding of carrier tape from the take-up reel, even if the magazine is separated from the test instrument; on the other hand, it is however precisely lifting movements that require even unwinding of carrier tape from the supply reel and from the take-up reel in order, for example, to enable a tension-free lifting movement of the test element.
The solutions known from the prior art, such as, for example, the one in International Publication No. WO 2006/059232 A1, in which a rewind lock is by-passed when the magazine is inserted into the test instrument, are, in part, technically very complex. Such releases would furthermore generally lead to released tape material being fixed loosely after the piercing and possibly falling out of a tape guide. A correspondingly complex control of the take-up reel drive could compensate for these circumstances.